Note that the _asdict() method is outdated

Doc/library/collections.rst

@@ -771,9 +771,10 @@ field names, the method and attribute names start with an underscore.
 .. method:: somenamedtuple._asdict()
 
     Return a new :class:`OrderedDict` which maps field names to their corresponding
-   values::
+    values.  Note, this method is no longer needed now that the same effect can
+    be achieved by using the built-in :func:`vars` function::
 
-      >>> p._asdict()
+        >>> vars(p)
         OrderedDict([('x', 11), ('y', 22)])
 
     .. versionchanged:: 3.1